Prognostic factors in alcoholic cirrhosis with ascites were analyzed in a prospective study of 37 patients (25 men, 12 women), 26 of whom presented with clinically diagnosed ascites. A good therapeutic response following salt restriction was obtained in 50%; this response correlated well with an initially small ascites volume, male sex, daily urinary sodium excretion of greater than 10 mmol, plasma renin activity of less than 5 ng/ml/hr and a normal plasma aldosterone level. On the other hand, age, number of episodes and duration of ascites, hepatic functional parameters, plasma creatinine concentration and portal venous pressure had no predictive value as to therapeutic response. Patients' survival was inversely related to plasma renin activity and positively to sodium excretion. The one-year mortality rate reached 88% in patients with renin of greater than 5 ng/ml/hr or daily urinary sodium excretion of less than 10 mmol, while 70% of patients with renin of less than 5 ng/ml/hr or daily sodium excretion of greater than 10 mmol survived more than two years. No prognostic index of survival could be derived from age, sex, number of episodes, duration and volume of ascites, portal venous pressure or hepatic biochemical parameters. Thus, in cirrhotic alcoholic patients with ascites the determination of daily urinary sodium excretion, which is inversely related to the activity of the renin-angiotensin system, provides a useful prognostic index for the response to salt restriction and longterm survival.